The patch titled
ext3 balloc: fix _with_rsv freeze
has been added to the -mm tree. Its filename is
ext3-balloc-fix-_with_rsv-freeze.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: ext3 balloc: fix _with_rsv freeze
From: Hugh Dickins <[email protected]>
After several days of testing ext3 with reservations, it got caught inside
ext3_try_to_allocate_with_rsv: alloc_new_reservation repeatedly succeeding
on the window [12cff,12d0e], ext3_try_to_allocate repeatedly failing to
find the free block guaranteed to be included (unless there's contention).
Fix the range to find_next_usable_block's memscan: the scan from "here"
(0xcfe) up to (but excluding) "maxblocks" (0xd0e) needs to scan 3 bytes not
2 (the relevant bytes of bitmap in this case being f7 df ff - none 00, but
the premature cutoff implying that the last was found 00).
Is this a problem for mainline ext3? No, because the "size" in its memscan
is always EXT2_BLOCKS_PER_GROUP(sb), which mkfs.ext3 requires to be a
multiple of 8. Is this a problem for ext3 or ext4? No, because they have
an additional extN_test_allocatable test which rescues them from the error.
Signed-off-by: Mingming Cao <[email protected]>
Signed-off-by: Hugh Dickins <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---
fs/ext3/balloc.c | 2 +-
1 files changed, 1 insertion(+), 1 deletion(-)
diff -puN fs/ext3/balloc.c~ext3-balloc-fix-_with_rsv-freeze fs/ext3/balloc.c
--- a/fs/ext3/balloc.c~ext3-balloc-fix-_with_rsv-freeze
+++ a/fs/ext3/balloc.c
@@ -730,7 +730,7 @@ find_next_usable_block(ext3_grpblk_t sta
here = 0;
p = ((char *)bh->b_data) + (here >> 3);
- r = memscan(p, 0, (maxblocks - here + 7) >> 3);
+ r = memscan(p, 0, ((maxblocks + 7) >> 3) - (here >> 3));
next = (r - ((char *)bh->b_data)) << 3;
if (next < maxblocks && next >= start && ext3_test_allocatable(next, bh))
_
Patches currently in -mm which might be from [email protected] are
git-powerpc.patch
__unmap_hugepage_range-add-comment.patch
shared-page-table-for-hugetlb-page-v4.patch
htlb-forget-rss-with-pt-sharing.patch
mlock-cleanup.patch
always-print-out-the-header-line-in-proc-swaps.patch
reject-corrupt-swapfiles-earlier.patch
kill-install_file_ptes-pte_val.patch
honour-mnt_noexec-for-access.patch
ext3-fix-reservation-extension.patch
ext4-fix-reservation-extension.patch
ext3-balloc-reset-windowsz-when-full.patch
ext3-balloc-fix-off-by-one-against-grp_goal.patch
ext3-balloc-fix-off-by-one-against-rsv_end.patch
ext3-balloc-say-rb_entry-not-list_entry.patch
ext3-balloc-use-io_error-label.patch
ext3-balloc-fix-_with_rsv-freeze.patch
ext2-reservations.patch
ext2-balloc-fix-_with_rsv-freeze.patch
ext2-balloc-reset-windowsz-when-full.patch
ext2-balloc-fix-off-by-one-against-rsv_end.patch
ext2-balloc-fix-off-by-one-against-grp_goal.patch
ext2-balloc-say-rb_entry-not-list_entry.patch
ext2-balloc-use-io_error-label.patch
generic-bug-implementation.patch
generic-bug-implementation-handle-bug=n.patch
generic-bug-for-i386.patch
generic-bug-for-x86-64.patch
bug-test-1.patch
tty-switch-to-ktermios-powerpc-fix.patch
On Wed, 29 Nov 2006, [email protected] wrote:
>
> The patch titled
> ext3 balloc: fix _with_rsv freeze
> has been added to the -mm tree. Its filename is
> ext3-balloc-fix-_with_rsv-freeze.patch
>
> See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
> out what to do about this
>
> ------------------------------------------------------
> Subject: ext3 balloc: fix _with_rsv freeze
> From: Hugh Dickins <[email protected]>
>
> After several days of testing ext3 with reservations, it got caught inside
> ext3_try_to_allocate_with_rsv: alloc_new_reservation repeatedly succeeding
> on the window [12cff,12d0e], ext3_try_to_allocate repeatedly failing to
> find the free block guaranteed to be included (unless there's contention).
Thanks a lot for changing the comments on these twelve, substituting
ext3 or ext4 for ext2 where appropriate: I much prefer these.
But in the case of this ext3-balloc-fix-_with_rsv-freeze.patch and
the ext4-balloc-fix-_with_rsv-freeze.patch, the resulting comment
goes wrong: there's never been such a freeze in ext3 or ext4.
I suggest a better comment for this ext3 one would be something
like the below - I trust you to deduce the ext4 comment!
Port fix to the off-by-one in find_next_usable_block's memscan from
ext2 to ext3; but it didn't cause a serious problem for ext3 because
the additional ext3_test_allocatable check rescued it from the error.
Hugh
>
> Fix the range to find_next_usable_block's memscan: the scan from "here"
> (0xcfe) up to (but excluding) "maxblocks" (0xd0e) needs to scan 3 bytes not
> 2 (the relevant bytes of bitmap in this case being f7 df ff - none 00, but
> the premature cutoff implying that the last was found 00).
>
> Is this a problem for mainline ext3? No, because the "size" in its memscan
> is always EXT2_BLOCKS_PER_GROUP(sb), which mkfs.ext3 requires to be a
> multiple of 8. Is this a problem for ext3 or ext4? No, because they have
> an additional extN_test_allocatable test which rescues them from the error.
>
> Signed-off-by: Mingming Cao <[email protected]>
> Signed-off-by: Hugh Dickins <[email protected]>
> Cc: <[email protected]>
> Signed-off-by: Andrew Morton <[email protected]>
> ---
>
> fs/ext3/balloc.c | 2 +-
> 1 files changed, 1 insertion(+), 1 deletion(-)
>
> diff -puN fs/ext3/balloc.c~ext3-balloc-fix-_with_rsv-freeze fs/ext3/balloc.c
> --- a/fs/ext3/balloc.c~ext3-balloc-fix-_with_rsv-freeze
> +++ a/fs/ext3/balloc.c
> @@ -730,7 +730,7 @@ find_next_usable_block(ext3_grpblk_t sta
> here = 0;
>
> p = ((char *)bh->b_data) + (here >> 3);
> - r = memscan(p, 0, (maxblocks - here + 7) >> 3);
> + r = memscan(p, 0, ((maxblocks + 7) >> 3) - (here >> 3));
> next = (r - ((char *)bh->b_data)) << 3;
>
> if (next < maxblocks && next >= start && ext3_test_allocatable(next, bh))
> _
>
> Patches currently in -mm which might be from [email protected] are
>
> git-powerpc.patch
> __unmap_hugepage_range-add-comment.patch
> shared-page-table-for-hugetlb-page-v4.patch
> htlb-forget-rss-with-pt-sharing.patch
> mlock-cleanup.patch
> always-print-out-the-header-line-in-proc-swaps.patch
> reject-corrupt-swapfiles-earlier.patch
> kill-install_file_ptes-pte_val.patch
> honour-mnt_noexec-for-access.patch
> ext3-fix-reservation-extension.patch
> ext4-fix-reservation-extension.patch
> ext3-balloc-reset-windowsz-when-full.patch
> ext3-balloc-fix-off-by-one-against-grp_goal.patch
> ext3-balloc-fix-off-by-one-against-rsv_end.patch
> ext3-balloc-say-rb_entry-not-list_entry.patch
> ext3-balloc-use-io_error-label.patch
> ext3-balloc-fix-_with_rsv-freeze.patch
> ext2-reservations.patch
> ext2-balloc-fix-_with_rsv-freeze.patch
> ext2-balloc-reset-windowsz-when-full.patch
> ext2-balloc-fix-off-by-one-against-rsv_end.patch
> ext2-balloc-fix-off-by-one-against-grp_goal.patch
> ext2-balloc-say-rb_entry-not-list_entry.patch
> ext2-balloc-use-io_error-label.patch
> generic-bug-implementation.patch
> generic-bug-implementation-handle-bug=n.patch
> generic-bug-for-i386.patch
> generic-bug-for-x86-64.patch
> bug-test-1.patch
> tty-switch-to-ktermios-powerpc-fix.patch